Frozen shrimp are sleeping, not dead. Wake them up gently. Dump them in a colander and run cold water over them for five minutes.
Never use hot water. That turns your shrimp into rubber bands. You want bouncy, not bounce-off-the-wall.
Pat them dry with a paper towel. Why? Wet shrimp steam. Dry shrimp sizzle. You want sizzle. Always.